1 Scope
This standard specifies the structural types, technical requirements, test methods, inspection rules, marking and packaging of steel undee spring used in electric machines (hereinafter referred to as “undee spring”).
This standard is applicable to basic series and its subseries of small and medium asynchronous electric machines, and also applicable to steel undee springs used in other equipment that requires axial preload.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this standard. However parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 90.1-2002 Fasteners - Acceptance inspection (idt ISO 3269: 2000)
GB/T 191-2000 Packaging - Pictorial marking for handling of goods (eqv ISO 780: 1997)
GB 755-2000 Rotating electrical machines - Rating and performance (idt IEC 60034-1:1996)
GB/T 2828.1-2003 Sampling procedures for inspection by attribute - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection (ISO 2859-1:1999; IDT)
GB/T 2829-2002 Sampling procedures and tables for periodic inspection by attributes (Apply to inspection of process stability)
YB/T 5058-1993 Cold-rolled spring and tool steel strips
3 Structural types
The undee spring is an elastic element with several undee peaks and valleys on a metal sheet ring, and its shape is shown in Figure 1.
Contents
Foreword I
1 Scope
2 Normative References
3 Structural Types
4 Technical Requirements
5 Test Methods
6 Inspection Rules
7 Marking and Packaging